The lib/required/ directory contains all the JARs Hibernate requires. All the
jars in this directory must also be included in your project's classpath.

The /lib/jpa/ directory contains the
hibernate-entitymanager jar and its dependencies beyond those
in lib/required/. This defines Hibernate support for
JPA.

The lib/envers directory contains the hibernate-envers
jar and its dependencies beyond those in lib/required/

The lib/optional directory contains the jars needed for optional features of
Hibernate.

1.2. Maven Repository Artifacts

Note

The authoritative repository for Hibernate artifacts is the JBoss Maven repository. The team responsible
for the JBoss Maven repository maintains a number of Wiki pages that contain important information.